/** * Calculates the sum for a set of data. * @since 6.5.0 */Ext.define('Ext.data.summary.Sum', { extend: 'Ext.data.summary.Base', alias: 'data.summary.sum', /** * Name of the summary function that appears in the {@link Ext.grid.plugin.Summaries} plugin */ text: 'Sum', calculate: function(records, property, root, begin, end) { var n = end - begin, i, sum, v; for (i = 0; i < n; ++i) { v = this.extractValue(records[begin + i], property, root); sum = i ? sum + v : v; } return sum; }});